全文获取类型
收费全文 | 1047篇 |
免费 | 45篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 31篇 |
妇产科学 | 5篇 |
基础医学 | 77篇 |
口腔科学 | 140篇 |
临床医学 | 57篇 |
内科学 | 157篇 |
皮肤病学 | 66篇 |
神经病学 | 63篇 |
特种医学 | 56篇 |
外科学 | 210篇 |
综合类 | 26篇 |
预防医学 | 45篇 |
眼科学 | 27篇 |
药学 | 86篇 |
中国医学 | 3篇 |
肿瘤学 | 39篇 |
出版年
2023年 | 6篇 |
2021年 | 27篇 |
2020年 | 13篇 |
2019年 | 23篇 |
2018年 | 34篇 |
2017年 | 15篇 |
2016年 | 34篇 |
2015年 | 21篇 |
2014年 | 37篇 |
2013年 | 47篇 |
2012年 | 68篇 |
2011年 | 65篇 |
2010年 | 30篇 |
2009年 | 21篇 |
2008年 | 47篇 |
2007年 | 42篇 |
2006年 | 47篇 |
2005年 | 49篇 |
2004年 | 38篇 |
2003年 | 32篇 |
2002年 | 39篇 |
2001年 | 29篇 |
2000年 | 35篇 |
1999年 | 23篇 |
1998年 | 9篇 |
1997年 | 10篇 |
1995年 | 14篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 17篇 |
1991年 | 21篇 |
1990年 | 9篇 |
1989年 | 11篇 |
1988年 | 17篇 |
1987年 | 15篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 13篇 |
1983年 | 9篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 13篇 |
1976年 | 3篇 |
1975年 | 10篇 |
1974年 | 9篇 |
1973年 | 4篇 |
1972年 | 15篇 |
1971年 | 5篇 |
1970年 | 3篇 |
1969年 | 8篇 |
排序方式: 共有1094条查询结果,搜索用时 31 毫秒
1.
Maninder S Kalkat Ishtiaq Rahman Kostas Kotidis Ben Davies Robert S Bonser 《European journal of cardio-thoracic surgery》2007,32(2):250-254
BACKGROUND: In Marfan's syndrome, there is a paucity of data regarding intervention criteria for surgery of the dissected thoraco-abdominal aorta. METHODS: A retrospective analysis of 22 Marfan's patients with distal aortic dissection managed between September 1999 and April 2006 was performed. Serial diameters and linear expansion rates were calculated from imaging studies and the outcome of intervention was analysed. RESULTS: There were 14/22 male patients (median age 38 years), and 18 had prior aortic surgery. Surgery was recommended in 20 patients and undertaken in 19 (1 died prior to operation). Of the operated patients, 2 presented with rupture, 2 with airway obstruction, 1 with intermittent paraplegia and 14 underwent planned surgery for increased expansion rate or pain. All patients had residual type A or chronic type B dissection. The median aortic dimension at surgery was 6.7 cm (interquartile range (IQR) 5.5-8.2). The preoperative mean expansion rate increased from 0.5 cm/year to 1.7 cm/year (p<0.001), prior to operation. Fifteen patients underwent Crawford Extent II, two underwent Extent I and two underwent Extent III repair. Profound hypothermia and CSF drainage was used in 16 and 18 patients, respectively. There was no early mortality, paraplegia or renal failure. At a median postoperative follow-up of 56 months (range 6-86), the survival of the operated cohort was 90%. CONCLUSIONS: Thoraco-abdominal aortic aneurysm repair in Marfan's syndrome can be performed with good outcomes. Intervention should be based on size or accelerated expansion. Any role of endovascular management needs careful consideration. 相似文献
2.
3.
4.
Five hybridoma cell lines were established that secrete monoclonal antibodies (MAbs) directed against rat plasma low molecular weight plasma kininogen. Two of the secreted antibodies were of the IgG1k isotype. The remaining three were of the IgG1 lambda, IgG2ak and IgMk isotypes, respectively. The dissociation constants (Kd) of these MAbs ranged from 0.58 X 10(-9) M to 5.4 X 10(-9) M. At least two distinct epitopes on the rat plasma kininogen were recognized by these MAbs. Further characterization of the MAbs showed that four MAbs cross-reacted strongly with kininogen from the Murphy-Sturm lymphosarcoma (MSLS) tumor while one of the MAbs cross-reacted weakly with MSLS tumor kininogen. 相似文献
5.
Transformation of immortal, non-tumorigenic osteoblast-like human osteosarcoma cells to the tumorigenic phenotype by nickel sulfate 总被引:5,自引:2,他引:3
Rani A.Shobha; Qu Da-Qin; Sidhu Maninder K.; Panagakos Fotinos; Shah Varsha; Klein Kenneth M.; Brown Nicholas; Pathak Sen; Kumar Suriender 《Carcinogenesis》1993,14(5):947-953
Epidemiological studies have indirectly linked compounds ofchromium, nickel and arsenic to human carcinogenesis. However,there is no evidence that metal compounds can transform humancells to the tumorigenic phenotype in culture. We show herethat exposure to 36 µM NiS04 for 4896 h resultsin transformation of an immortal, non-tumorigenic, osteoblast-likecell line, HOS TE85, to the tumorigenic phenotype. Continuouspassaging following treatment leads to the formation of a fewdense foci. The cells isolated and expanded from the foci aremorphologically transformed, and form anchorage-independentcolonies of the size and abundance comparable to that formedby Kirsten murine sarcoma virus transformed HOS TE85 cells.The transformed cells from tumors in nude mice, have enhancedlevels of plasminogen activators and have lost the ability toform model bone matrix on extended culture in the presence ofascorbic acid and ß-glycerophosphate. A number ofcell lines have been established from nude mouse tumors. Cytogeneticanalysis reveals 16 marker chromosomes and an aberrant chromosome16. This is the first report of the transformation of a humancell line to tumorigenic phenotype by a metal carcinogen. 相似文献
6.
7.
A case of placenta membranacea, previa and accreta was managed conservatively and resulted in delivery of a mature fetus. The diagnosis of placenta membranacea and previa was obtained with ultrasound. The placenta previa and accreta necessitated a cesarean delivery and hysterectomy. 相似文献
8.
The aim of this study was to determine the self-reported preventive oral health related behaviours of dentally anxious schoolchildren. 1103 children participated in the study, mean age 14 years (SD 0.35 years), and the prevalence of high dental anxiety was 7.1 per cent (95 per cent confidence interval = 5.6 per cent, 8.6 per cent). Children with high self reported dental anxiety were more likely to defer, cancel and or not attend dental appointments. In addition, for this group the last dental visit was more likely to be as a result of pain and less likely to have been for a dental examination only. Overall dentally anxious children did not help themselves by keeping their teeth clean. Fluorides were infrequently used by all the children, and only 12 per cent of all who participated in the study used fluoride supplements regularly. In this context it is not surprising that no differences in present or past use of fluoride supplements could be determined between high and low/moderate dental anxiety groups. The high dental anxiety group spend significantly more (median = 50p) on sweets per day and drank more cans of fizzy drinks (median = 2) compared with the low/moderate anxiety groups. These effects were significant after taking into account social class and gender differences. It was clear from the study that even when social class and gender are taken into account the children with high dental anxiety were not helped by their relatively poor attitudes towards preventing disease in their own mouths. 相似文献
9.
Impact of therapeutic management on use of seclusion and restraint with disruptive adolescent inpatients 总被引:1,自引:0,他引:1
Use of seclusion and restraint on three inpatient adolescent psychiatric units was examined during two five-month periods before and after implementation of a "therapeutic management" protocol. Under the protocol, staff classified disruptive behaviors into four stages and provided verbal and behavioral interventions to control behavior at each stage. Patients who required seclusion and restraint had significant latitude to determine the timing of their release from the interventions and met with staff one hour and 24 hours after their release to explore alternatives to aggression. The number of episodes of seclusion and restraint fell by 64 percent after the protocol was adopted, and the number of patients who required those interventions dropped by 39 percent. The mean duration of episodes of seclusion and restraint was reduced by 59 percent. Therapeutic management provides a corrective experience by addressing the developmental needs, deficient cognitive skills, and poor internalized controls of disruptive adolescents. 相似文献
10.
Recent research has shown that a lengthy period of undernutrition during early postnatal life can cause alterations in the morphological structure of the dentate gyrus. As this region is involved in the control of spatial memory, we decided to investigate whether undernourished rats also showed any deficits in this aspect of behaviour. Rats were undernourished from about birth until either 30 or 60 days of age and then nutritionally rehabilitated for a lengthy period before testing. There were significant differences in the body weight of control and undernourished rats in each experiment. The testing procedure involved rats being placed in a large pool of opaque water. They were required to swim to find a hidden platform located just below the water surface onto which they could escape. Each rat had to perform this test 20 times over a period of 3 days. The time taken and the total distance swum by each rat during each trial was measured. In Experiment 1, rats were familiarised with the water before testing took place, whereas in Experiment 2 they were not. There were no significant differences in the latency to find the platform or the distance swum between well-fed control and previously undernourished rats in either experiment. In conclusion, in our experiments we could not demonstrate that undernutrition during early life caused any deficits in spatial memory performance. 相似文献